1. Field of the Invention
The present invention relates to reciprocating engines, and more particularly to a dwell cycle crank configuration that efficiently utilizes energy to convert reciprocating linear motion to rotary motion or vice versa.
2. Description of the Related Art
A conventional internal combustion engine (ICE) having a piston cylinder attached to a crank armor yoke offset from the crank shaft proceeds through various processes in a typical cycle; intake, compression, power, and exhaust. In a four-stroke engine, each process occurs in each stroke of the piston, i.e. first stroke (downward) corresponds to an intake process or charging of a fuel-air mixture, second stroke (upward) corresponds to a compression process of the mixture, third stroke (downward) corresponds to 15 a power process in which the mixture is ignited to produce energy for turning the crank, and fourth stroke (upward) corresponds to the exhaust process which vents the waste products of combustion from the piston chamber. The directions indicated above in parentheses are mainly illustrative of a configuration in which the piston cylinder is arranged to reciprocate in a vertical orientation. It is noted that many conventional ICEs include various configurations of pistons that depart from vertical.
Another common type of ICE is a two-stroke engine in which-two of the four processes mentioned above occur in the same stroke. For example, the first stroke (downward) includes the intake and power processes while the second stroke (upward) includes the compression and exhaust processes.
The efficiency of any of the above mentioned engines is measured in part by how an engine maximizes the thermo energy produced via combustion, since an ICE is fundamentally a practical application of heat transfer thermodynamics. It is recognized that many factors are involved in determining the efficiency of an ICE, e.g. the crank and piston geometry, compression ratios, charge durations, burn durations, engine tuning parameters, air-fuel mixture, engine block temperature, etc. However, one of the main factors for inefficient operation in an engine is potential heat loss during a cycle. Some attributing examples may be mistimed ignition of the air-fuel mixture that results in less than maximum consumption of the resource and thereby produce sub-optimal power to turn the crank, or simple heat loss between the piston cylinder chamber and the surrounding engine block and/or other attached components. Hence, most commercial engines in vehicles have roughly 20% efficiency. Due to current economics and dwindling resources, there exists a need for more efficient engines.
Thus a dwell cycle crank solving the aforementioned problems is desired.